What is the Oxford Comma?

Author: Michael L.

Date: Jun 17, 2019 | Grammar

What is the Oxford Comma and Why is it Important? The Oxford comma, which is sometimes referred to as a serial comma, is the final comma in a sentence containing list of things, usually coming before and or or. It is used for clarity in a sentence, and its use is often a matter of style, sometimes causing disagreement in publishing and literary circles. Look at the examples below:
  • I like Jim, John, Jean, Leo, and Mary, all my cousins from New York.
  • We refuse to the sign a treaty with Russia, Canada, Mexico, or Australia.
The comma coming after Leo and Mexico are the Oxford commas. What purpose do they serve here? In these cases, the Oxford comma’s inclusion is simply a matter of style. The following versions are also correct:
  • I like Jim, John, Jean, Leo and Mary.
  • We refuse to the sign a treaty with Russia, Canada, Mexico or Australia.
There is no difference to the meaning of the examples above, but some publications stress you should use the Oxford comma, whereas others ask you to omit it. For example, the United States Government Printing Office says you should use the Oxford comma, whereas The Economist Style Guide opposes typical use. Meanwhile, the Guardian Style Guide cites the Oxford comma as unnecessary, but accepts that its use is at the writer’s discretion. So, while it might be a question of style, the Oxford comma does have some important uses. Consider the next example which does not use an Oxford comma.
  • Emma got angry at her parents, David and Anna.
This sentence might suggest to the reader that Emma became angry with her parents, who are called David and Anna. But what if we are trying to convey that Emma got angry with her parents, as well as two other people who are called David and Anna? That is where the Oxford comma comes in to help stop confusion.
  • Emma got angry at her parents, David, and Anna.
Stylists who do not like the Oxford comma may ask the sentence to be written in a different way to cause less confusion:
  • Emma got angry at David, Anna and her parents.
Look how different the sentence would seem, if this is what was written, and we thus understood that God and Lady Gaga were her parents:
  • Emma got angry at her parents, God and Lady Gaga.
However, while the Oxford comma might be a question of style, i.e. it is up to you whether you use it, it nevertheless is considered important for clarity as in the sentence above and especially when it comes to the interpretation of legal texts. A company in Maine famously lost a multi-million-dollar lawsuit on paying workers overtime because of an omitted Oxford comma. The text in question is shown below:
  • [Workers would not be paid overtimes when engaged in:] The canning, processing, preserving, freezing, drying, marketing, storing, packing for shipment or distribution of:
    (1) Agricultural produce;
    (2) Meat and fish products; and
    (3) Perishable foods.
If there had been an Oxford comma after the word shipment, which would have distinguished between shipment and distribution as separate activities, the company may have won the case against its workers. But since it did not, the case was won on the side of the employees.   Oxford Comma Examples
The following examples show how the meaning of sentences can be changed with the addition of the Oxford comma: Without Oxford comma
  • My favorite things to eat and drink are: Eggs, tomatoes, bread, wine and cheese.
The inference above might be that wine and cheese are only enjoyed when taken together. The Oxford comma used below shows that wine and cheese can be enjoyed separately.
  • My favorite things to eat and drink are: Eggs, tomatoes, bread, wine, and cheese.
Without Oxford comma
  • Top stories: World leaders at Mandela tribute, Obama-Castro handshake and same-sex marriage date set…
The above example is from a real Sky News push notification. Without the Oxford comma it might cause confusion that Barack Obama and Fidel Castro had a handshake and set a date for their wedding. Unlikely, you’ll agree, but an Oxford comma saves confusion.
  • Top stories: World leaders at Mandela tribute, Obama-Castro handshake, and same-sex marriage date set…
Please note: You never use an Oxford comma if the list only contains two items, except if it is to stop confusion.
  • I love the music of Iron Maiden and Metallica. Correct
  • I love the music of Iron Maiden, and Metallica. Incorrect
However, if there is confusion:
  • I love the music of Buddy Holly and Tom Petty and the Heartbreakers.
Tom Petty and the Heartbreakers is a single entity but the extra and in the band’s name causes confusion here, so we use the Oxford comma to make that clear:
  • I love the music of Buddy Holly, and Tom Petty and the Heartbreakers.
A final example of the Oxford comma in action: Consider this example, which again uses musicians:
  • We adore the music of John, Paul, George and Ringo.
John, Paul, George and Ringo are, of course, the Beatles. But does the above sentence convey that we like the music of the Beatles, or each musician’s work separately? If we rewrote the sentence with the Oxford comma, it would look like this:
  • We adore the music of John, Paul, George, and Ringo.
One could argue that the Oxford comma tells us that we like the music produced by each musician separately, whereas the sentence without the Oxford comma is simply saying we like the music of the Beatles. It’s very subtle, of course, but the Oxford comma is acting here as if to say and Ringo’s music too. It’s open to interpretation and becomes a question of style, but the Oxford comma can be very important.